The present invention relates to a holding device for a chain, particularly for a chain associated with a coal cutter.
Chain blocks for holding chains have been proposed in the art, which blocks are formed as massive elongated rectangular-shaped members of steel, and are of a welded or forged construction. The shaped member is provided with a chain holding dog extending laterally beyond the shaped member. An end link of the chain or a longitudinal element of a chain swivel is suspended on the above dog. A mounting lug or another mounting dog is arranged at the other end of a body part of the coal cutter, for a guide bar or for a safety chain. The guide bar or the safety chain serve for connecting the chain block with another chain block which is provided at the other end of the coal cutter.
Practical use of the above device has shown that the chain holding dogs are frequently torn off under stresses applied thereto under extreme geological conditions, especially in the case of steep stratification, in spite of the fact that they are extremely massively mounted on blocks of coal cutter tongues. When the chain is torn off at a downstream location (relative to the machine), it is no longer in control, due to its own weight and due to the pulling force acting upon it after it tears away from the chain holding dogs. Thus, the torn off end portions of the chain must be located in the mine and returned to the chain block. Furthermore, the projecting portions of the chain holding dogs endanger safety in the mine. Moreover, forged links located between outer portions and middle portions of the coal cutter are destroyed as often as the chain holding dogs are torn off. After this it is not possible to withdraw the coal cutter with the desired degree of mobility.